Up to now, an electronic key system that executes various controls such as locking and unlocking doors on the basis of a successful matching performed based on a wireless communication between a vehicle-mounted device and a mobile terminal or a matching failure has been known.
As the above-described electronic key system, a system may be configured as follows. In a situation where all of the doors of a vehicle are in closed state and at least one door is in unlocked state, when the mobile terminal moves out of a wireless communication range of the vehicle-mounted device, all of the doors are locked automatically. Hereinafter, for description convenience, a system in which all of the doors are automatically locked when the mobile terminal moves out of the wireless communication range of the vehicle-mounted device is referred to as an automatic locking system.
The vehicle-mounted device of the electronic key system employing the automatic locking system sequentially transmits signals to the mobile terminal at a predetermined transmission period, and determines that the mobile terminal moves out of the wireless communication range of the vehicle-mounted device when the vehicle-mounted device can no longer receive a response to the signals transmitted from the mobile terminal. Therefore, in the electronic key system employing the automatic locking system, the transmission and reception of the signals are sequentially executed between the vehicle-mounted device and the mobile terminal for the purpose of determining whether the mobile terminal moves out of the wireless communication range or not.
Patent Literature 1 discloses a configuration in which a sensor that detects user's intentional operation (unlocking operation) for not automatically locking the door even when the mobile terminal moves out of the wireless communication range. In Patent Literature 1, the sensor is disposed in a vicinity of each door handle. In the electronic key system of Patent Literature 1, when an unlocking operation made by the user is detected by the sensor, the automatic locking of the doors is not carried out. As a result, the above configuration can reduce the likelihood of unintentional door locking which is against user's intention.